Press



Nov. 26, 1940. E. M. WINEGAR PRESS Filed Sept. 21, 1937 2 Sheets-Sheet 1.w I I I l l f INVENTOR.

p w w f my Nov. 26, 1940. E. M. WINEGAR PRESS Filed Sept. 21, 1937 2Sheets-Sheet 2 INVENTOR. BY fDMl/IYD M W/YAd/M fluid %/admfl1 w MATTORNEYS Patented Nov, 26, 1940 UNITED STATES PATENT OFFICE PRESSApplication September 21, 1937, Serial No. 164,902

Claims.

The present invention relates to presses, especially vulcanizingpresses, and to improved means for controlling the operation thereof.

I In the operation of the presses, especially 5 those employed formolding plastics, vulcanizing,

and the like, it is customary to release the pressure on the molds oropen the same slightly for a short interval of time after the closingthereof, either once or a plurality of times, the purpose of which is toallow any air which might be trapped in the molds to escape, or topermit a rearrangement of the stock in the molds, etc. This operation iscommonly referred to as bumping and in fluid pressure actuated pressesis ordinarily performed by a manually controlled valve located at someconvenient place on the press. Devices have been devised to perform thisbumping operation automatically but these devices have provedunsatisfactory for various reasons, such as inability to maintain therequired control over the amount that the press or molds open upon eachbumping operation.

An object of the present invention is the provision of a novel means forbumping a fluid pressure actuated press, especially a vulcanizing press,in which the required control over the press is maintained at all times.

Another object of the present invention is the provision of a novelcontrol for a fluid pressure actuated press, especially a vulcanizingpress, which control includes means for automatically bumping the presswhile maintaining the required control over the press.

Another object of the present invention is the provision of a novelautomatic fluid pressure actuated press, especially a vulcanizing press,over which the desired control is maintained at all times and whichincludes means for automatically bumping the same.

Further objects and advantages of the present invention will be apparentto those skilled in the art to which it relates from the followingdescription of the preferred embodiment thereof 45 described withreference to the accompanying drawings forming a part of thisspecification in which similar reference characters designatecorresponding parts, and in which Fig. 1 is a side elevation of avulcanizing press 5 embodying the present invention; and

Fig. 2 is a schematic diagram of the control system therefor.

While the invention is susceptible of various modifications andalternative constructions, it is 55 herein illustrated and described asembodied in a double deck vulcanizing press. Generally speaking, thepress comprises two pairs of platens IO and II, and I2 and [3 adapted tocarry mold members on the adjacent faces thereof. The platens aremovably supported on two sets of runway brackets l5 and I6, and I1 andI8, in such a manner that they can be moved into the press proper forperforming the molding and vulcanizing operation and out of the pressproper for facilitating the loading and unloading of the molds. Therunway brackets l5 and I6 and I1 and I8 are vertically offset andproject from the opposite side of the press so that the molds can besimultaneously loaded and unloaded by operators at opposite sidesthereof, thereby reducing the time required to perform the loadingoperation.

The press proper consists of a base 22 and a stationary abutment memberor upper head 23 held in predetermined spaced relation above the base byside plates or strain members 24. The runway brackets [5 are carried bya lower head 25 positioned underneath the head 23 and connected to theupper end of a piston or ram 25 5 slidably supported in a cylinderformed in the base 22. The runway brackets l6 and I! are carried by avertically movable floating member or head 21 positioned midway betweenthe stationary upper head 23 and the movable lower head 25. The pair ofplatens Ill and II which constitute the lower deck of the press arehinged together through a lost motion connection and. are adapted to bemoved into and out of the press by an electric motor 30 through themedium of a lead screw (not shown) having threaded engagement with a nutsecured to the underside of the bottom platen 10. When the platens Inand H are within the press proper, they are located above the movablehead 25 and underneath the floating or vertically movable head 21. Theplatens I2 and I3 which constitute the upper deck of the press arelikewise hinged together through a lost motion connection and areadapted to be moved into and out of a position intermediate thestationary upper head 23 and the floating member or head 21, by anelectric motor 3| operatively connected to the platen l2 in a mannersimilar to that in which the motor 30 is connected to the platen Ill.The electric motors 3|] and 3| are supported on the brackets fixed tothe rear sides of the heads 25 and 21 respectively. As previouslystated, the lower runway brackets l5 of the lower deck are attached tothe lower head 25 and move therewith. The upper runway brackets I6 ofthe lower deck and the lower runway brackets I! of the upper deck arecarried by the floating head 21 and move therewith. The upper runwaybrackets l8 of the upper dec are fixed to the stationary head 23.

Positive means for opening the press is provided in the form of fluidpressure actuated :motors 35 supported on the side members or plates 24above the upper head 23. The motors 35 are operatively connected to thelower head 25 by rods 31, the lower ends of which are secured in bosses38 projecting into cutout portions or apertures 39 in the side members24. The floatin head 21 is guided in its vertical movement by the rods3'! which extend through bosses 40 on either side of the floating headand the downward movement or lower position thereof is limited ordetermined by stop members 4| fixed to the side members or plates 24.

Fluid, preferably water, under high pressure is adapted to be suppliedfrom a conduit 49 to the cylinder in the base 22 for effecting theclosing of the press under the control of a fluid pressure actuatedthree-way diaphragm valve 48. The valve 48 is connected to the cylinderof the pressure fluid motor by conduit 50 and to a drain by conduit 5!.Fluid, preferably air, under relatively low pressure from a supply line53 is employed for operating the valve 48 through the medium of a branchline 54. The construction of the valve 48 is such that when pressurefluid is applied thereto through the line 54, the pressure fluid motorfor closing the press is connected with the supply line 49, and at allother times th motor is connected to an exhaust or a drain by theconduit 5|. The flow of air through line 54 is controlled by twonormally closed safety valves 55 and 56 connected in series with anormally closed three-way diaphragm valve 51, the the purpose of whichwill be hereinafter apparent. The normally closed safety valve 55 isfixed to the press in such a manner that it is opened bythe platens l0and H of the lower deck as they reach their in position, that is, theirposition within the press, and the valve 56 is fixed to the press insuch a manner that it is opened by the platens l2 and I3 of the upperdeck as they reach their in position. The construction is such that thediaphragm valve 5'! which controls the supply'of air for actuating thevalve 48 is not connected to the supply line until both pairs of platensor decks are properly positioned with in the press. When the diaphragmvalve 5? is in its normally closed position the load side thereof isopen to atmosphere through the conduit 58.

The electric motors 30 and 3| are adapted to be connected to the supplylines L L and L through solenoid operated reversing switches A and B,respectively, of the self-holding type. Preferably, the motors are ofthe three-phase alternating current type and are provided with magneticbrakes. The in solenoid 59 of the switch A, that is, the solenoid whichcloses the circuit to rotate the motor 35 in a direction to circuit thelower pair of platens l0 and I i into the press proper, is in serieswith a manually controlled push button switch BEIyin a switch box 6!fixed to the outside of one of the runway brackets l5. When the pushbutton 60 is released after being initially closed, the circuit to thesolenoid 59 is maintained energized through the holding circuit of theswitch A. When the platens reach their in position, the holding'circuitto the solenoid is broken by the opening of a normally closed limitswitch 54 in a switch box 55 secured to the press in such a manner as tobe actuated by the platens as they reach their in position.Simultaneously with the opening of the limit switch 64 the movement ofthe platens l0 and H closes a normally open switch 95 also locatedwithin the switch box 55. A single actuating lever operates both ofthese switches and the purpose of the switch 66 will be hereinafterapparent.

The in solenoid 5'! of the switch B is in series with a push buttonswitch 69 in a switch box Ill fixed to the outside of one of the runwaybrackets ll. After the push button switch has been operated to close thein solenoid of the switch B the circuit thereto is maintained energizedby the holding circuit of switch B. As the platens l2 and I3 of theupper deck reach their in position, the holding circuit for the solenoidM is opened by a normally closed limit switch it in a switch box 13, theactuating lever of which is adapted to be moved by the upper platen it.Simultaneously with the opening of the limit switch I? a normally openswitch 74 also located in the switch box 13 is closed by the movement ofthe platens. The latter switch 14 is in series with the switch 66, andwhen both of these switches are closed, a circuit is completed whichenergizes the motor of a time cycle device of commercial construction,designated generally by the reference character C, the operatingmechanism of which includes a cam 8i and a cam follower 82. The camfollower 82 is supported on a pivot 83 and oscillation thereof about thepivot under the control of the cam 8|, as will be hereinafter referredto, produces a vertical reciprocation of a bracket or frame 85 which, inturn, controls a plurality of three-way block air valves 85, 87, 88, and89 and two micro switches and 9t, the former of which is of the doublethrow type. The construction of the air valves 8t, 3?, 88, and 89 issuch that when the valves are in their closed positions the load sidesthereof are open to atmosphere through small apertures therein.

The bumping of the press effected in the following manner during theinitial rotation of the cam 8!, that is, while the cam follower 82 istraveling along the portion 92 of uniform rise, simultaneously with theclosing of the circuit to the motor 80 of the time cycle device, aseries circuit is closed to the automatic bumping solenoid-operatedvalve 93 through a normally closed hydraulic switch 94 and the normallyclosed lower contacts of the micro switch 90. When the solenoid valve 93is energized, it by-passes air from the supply line 53 to an air line 95leading to the valve 51 which in turn operates the diaphragm valve 48causing high pressure fluid to be admitted to the line 59 leading to thepress, thus causing the press to close. As soon as the pressure in theline 50 leading from the diaphragm valve 43 to the press cylinder and ina branch line 9! leading to the hydraulic switch 94 reaches apredetermined amount, the hydraulic switch opens, thus breaking thecircuit to the solenoid valve 93 allowing the same to return to itsinitial position and shutting off the supply of air to the valve 5?,causing the valve 48 to shut oif the supply of hydraulic fluid to thepress cylinder with the result that the press begins to open and thepressure in the molds is relieved. As soon as the pressure in the line55 falls to a certain point, the hydraulic switch 94 closes, againcausing pressure to be applied to the press. The hydraulic switch 94 isso set or adjusted that the press is subjected to substantially fullpressure before it actuates to open the circuit to the solenoid valve93, and again actuates to close the circuit when the pressure has fallena predetermined amount. During the interval that pressure is building upin the pneumatic control system to again actuate the valve 48 thepressure is relieved from the molds. Preferably this interval is ofsufficient length for the press to open slightly.

The pressure is relieved and then applied a number of times, that is,until the cam follower 82 rides up onto the raised portion 98 of the cam8|. The duration of the bumping operation, that is the number of thetimes the press is bumped, can be varied by an adjustable sector 98 onthe cam 8|. Movement of the cam follower raises the frame 85 a shortdistance to open the normally closed air valve 88 and supply air throughthe normally open valve 81, which is in series therewith, to thediaphragm valve 51 which, in turn, admits air to the second diaphragmvalve 48, thereby either closing the press or continuing the same closedas the case might be. Thereafter the circuit to the solenoid valve 93 ismaintained open by the continued high pressure applied to the hydraulicswitch 94. The initial upward movement of the frame 85 opens thenormally closed air valve 88, simultaneously with the actuation of thevalve 86 previously referred to, admitting air to the left hand end of acylinder I8I, thereby reciprocating or moving a rack I82 to the right asviewed in Fig. 2. This movement of the rack I82 advances or rotates thecam 8| an adjustable amount depending upon the location of a stop I83through a pawl and ratchet mechanism not shown. A friction clutchinterposed between the cam 8| and the motor 88 allows the cam 8| to beadvanced without affecting the motor drive. After the cam has beenadvanced by the rack I82 a predetermined amount, depending upon thelength of cure desired, it continues to rotate at a comparatively slowconstant speed under the control of the synchronous motor 88.

After the expiration of the allotted time the cam follower 82 travels upthe inclined portion or surface I85 of the cam 8| leading to the highestportion or surface II3. Movement of the frame 85 produced therebyactuates the micro switch 98 to open the normally closed contactsthereof and close the normally open contacts, which, in turn, closes thecircuit to a relay I86 the contacts of which are in series with normallyopen down limit switches I81 and I88 which remain open until the lowerhead 25 and floating head 21, respectively, are in their down position.As the cam follower 82 continues up the inclined portion or surface I85the frame 85 closes the normally open air valve 81 which in turnactuates the diaphragm valve 51 to reverse the diaphragm valve 48 toopen the press. The high surface 3 of the cam 8| is of sufficient lengthto maintain the normally open contacts of the micro switch 98 closedlong enough for the press to open. When the down limit switches I81 andI88 close, both pairs of platens automatically move to their outposition, that is, the position shown in Fig. l, at which time thecircuits to the motors 38 and 3| are opened by out limit switches I89and I I8, respectively. The down limit switches I81 and I88 are actuatedby the movement of the lower head 25 and the floating head 21,respectively, and the out limit switches, which are in series with theout solenoids III and H2 of the switches A and B, respectively, areactuated by the platens I8 and I2, respectively.

Subsequent to the actuation of the micro switch 98 the micro switch 9|is closed by the continued movement of the cam follower 82 along theinclined surface I85. This closes a circuit to the clock motor 88 whichcircuit is in parallel with the circuit to the clock motor 88 in whichthe contacts 66 and 14 of the limit switches 65 and 13 are located. Thepurpose of this circuit is to maintain the clock motor 80 energizedafter the contacts 66 and 14 of the limit switches 65 and 13 are openedupon the platens moving to their out position, thus continuing therotation of the cam 8| until the follower 82 drops off of the highportion or surface II3. When the cam follower 82 drops off the highlevel N3 the frame 85 returns to its original position, opening themicro switches 9|, thus breaking the circuit to the motor 68 stoppingthe clock, and the normally open air valve 89, which closed upon theinitial movement of the frame 85, thus admitting air to the opposite endof the cylinder I8I to reset the rack I82. Return of the frame 85 to itsoriginal or down position also opens the normally open contacts of themicro switch 98 breaking the circuit to the relay I86, and closes thenormally closed contacts of the micro switch 98 in series with thesolenoid valve 93.

A three-way valve I88 is provided for manually bumping the press if suchis desired. While in the preferred embodiment shown the bumpingoperation takes place upon the initial closing of the press, it will beapparent that any desired arrangement of the bumping operation may beobtained by constructing the cam 8| in the necessary manner.- In theembodiment shown the necessary lag required in the bumping operation isobtained in the pneumatic control system, but it is to be understoodthat this lag can be otherwise obtained, as by means of a time delaydevice. Air is supplied to the air valves 96, 81, 88 and 88 from theline 53 by a branch line II4. A pneumatic switch I I5 connected to theair line which connects the valve 81 and the pneumatic valve 51 causes asignal lamp 6 to burn while the press is closed. This gives a visualindication of the condition of the press, and it will be understood thatother signals may be employed as desired or the same may be omittedaltogether. Manually controlled push button switches I I1 and I I8 inthe switch boxes 6| and 18, respectively, permit either pair of platensto be moved out at will while the press is open. Similarly controlledpush button switches H9 and I28 also in the switch boxes 6| and 18,respectively, are provided for emergency use and permit the operation ofthe platens to be stopped at any time.

From the foregoing description of the preferred embodiment of theinvention it will be apparent that the objects of the inventionheretofore enumerated and others have been accomplished and that a novelcontrol means has been provided for automatically bumping a fluidpressure actuated press. Although the invention has been hereinillustrated and described as embodied in a vulcanizing press ofparticular construction, the invention is not limited to vulcanizingpresses or to the embodiment shown herein but is equally applicable toother fluid pressure actuated presses where it is desired to bump thepress. As previously stated the invention is not limited to theparticular construction shown and it is the intention to cover herebyall adaptations, modifications and variations thereof which come withinthe practice of those skilled in the art to which the present inventionrelates and within the spirit and scope of' the appended claims.

Having thus described my invention, I claim:

1. In a press, the combination of a pair of opposed press headsrelatively movable toward and away from each other, a. pressure fluidactuated motor for producing relative movement between said press heads,means for supplying to and exhausting pressure fluid from said motorincluding a valve, said valve when in one position serving to permitpressure fluid to exhaust from said motor to open the press, meansoperatively connected to said motor and controlled by the pressure offluid therein for actuating said valve to move to said position forexhaust when the pressure in said motor rises to a predetermined valuethereby causing the press to open and for moving said valve away fromsaid position for exhaust when the pressure in said motor drops to apredetermined value thereby causing the press to close upon supply ofpressure fluid to said motor, and means for rendering said last namedmeans inoperative and thus maintain the press closed.

2. In a press, the combination of a pair of opposed press headsrelatively movable toward and away from each other, a pressure fluidactuate-d motor for producing relative movement between said pressheads, means for supplying to and exhausting pressure fluid from saidmotor including a pressure fluid actuated valve, said valve when in oneposition serving to permit pressure fluid to exhaust from said motor toopen the press, means operatively connected to said motor and controlledby the pressure of fluid therein for actuating said valve to move tosaid position for exhaust when the pressure in said motor rises to apredetermined value thereby causing the press to open and for movingsaid valve away from said position for exhaust when the pressure in saidmotor drops to a predetermined value thereby causing the press to closeupon supp-1y of pressure fluid to said motor, and means for renderingsaid last named means inoperative and thus maintain the press closed.

3. In a press, the combination of a pair of opposed press headsrelatively movable toward and away from each other, a pressure fluidactuated motor for producing relative movement between said press heads,means for supplying to and exhausting pressure fluid from said motorincluding a pressure fluid actuated valve, said valve when in oneposition serving to permit pressure fluid to exhaust from said motor toopen the press, means including a pressure fluid actuated electricswitch operatively connected to said motor and controlled by thepressure of fluid therein and operatively connected to an electricsolenoid operated valve for actuating said pressure fluid actuated valvetomove to said position for exhaust when the pressure in said motorrises to a predetermined value thereby causing the press to open and formoving said valve away from said position for exhaust when the pressurein said motor drops to a predetermined value thereby causing the pressto close upon supply of pressure fluid to said motor, and means forrendering said last named means inoperative and thus maintain the pressclosed.

4. In a press, the combination of a pair of opposed press headsrelatively movable toward and away from each other, a pressure fluidactuated motor for producing relative movement between said press heads,means for supplying to and exhausting pressure fluid from said motorincluding a valve, said valve when in one position serving to permitpressure fluid to exhaust from said motor to open the press, meansoperatively connected to said motor and controlled by the pressure offluid therein for actuating said valve to move to said position forexhaust when the pressure in said motor rises to a predetermined valuethereby causing the press to open and for moving said valve away fromsaid position for exhaust when the pressure in said motor drops to apredetermined value thereby causing the press to close upon supply ofpressure fluid to said motor, means for subsequently rendering the lastmentioned means inoperative and thus maintain the press closed, andmeans for subsequently automatically opening the press after apredetermined time.

5. In a press, the combination of a pair of opposed press headsrelatively movable toward and away from each other, a pressure fluidactuated motor for producing relative movement between said press heads,means including a power actuated valve serving when in one position tooperatively connect said motor to a source of fluid pressure to closethe press and serving when in another position to permit pressure fluidto exhaust from said motor to open the press, means for moving saidvalve to the first mentioned position, and means operatively connectedto said motor and controlled by the pressure of fluid therein for movingsaid valve into the second mentioned position when the pressure in saidmotor rises to a predetermined value thereby causing the press to openand for again moving said valve into the first mentioned position whenthe pressure in said motor drops to a predetermined value therebycausing the press to close, and means for rendering said last namedmeans inoperative and thus maintain the press closed.

EDMUND M. WINEGAR.

